Collagen, the major structural protein of the soft and hard periodontal tissues, is disorganized and destroyed during periodontal disease. The objectives of the proposed project are to study the effects of inflammation and diabetes (a common systemic disorder thought to modify periodontal disease) on ginginval collagen metabolism in rats and humans. The project will consist of two phases. Phase I -inflammation of the gingiva of rats will be produced by injecting endotoxin or antigen-antibody complexes into these tissues. Inflammed and non-inflammed gingiva from control and alloxen-diabetic rats will be excised, and the concentration and solubility of collagen determined prior to incubation. In other experiments, gingival fragments will be cultured on collagen gels saturated with media containing H3-proline. Collagen synthesis will be determined by measuring H-hydroxyproline formation, and collagenolytic activity will be assessed by determining the amount of hydroxyproline solubilized from the gels as dialyzable fragments. Phase II - Collagenolytic activity in gingival crevice fluid from humans will be monitored in vitro, will be related to periodontal disease, and attempts will be made to determine its origin. In the future, gingival fragments from normal and diabetic patients undergoing routine periodontal surgery will be studied as in Phase I, after being scored for severity of gingival inflammation (gingival index, gingival crevice fluid flow). BIBLIOGRAPHIC REFERENCES: Gwinnett, A.J., Golub, L.M. and Kleinberg, I. 1975. Effect of a repeated prophylaxis on plaque accumulation and gingival crevice fluid flow. J. Dent. Res., 54, special issue A, abstract no. 605. Golub, L.M., Stakiw, J.E. and Singer, D.L. 1974. Collagenolytic activity of human gingival crevice fluid. J. Dent. Res., 53:1501.